High pressure devices such as compressors have component parts which are fitted together. Because of the high pressure that the unit contains, the parts that are fitted together generally have seals therebetween. In high pressure systems such as compressors, the pressure can gradually seep past a seal over extended periods of time. Thus, generally, two seals are placed in spaced relationship to each other to form an area in which the fluid that bypasses the first seal can collect. The second seal forms an effective barrier against further loss of pressure.
When the unit such as the compressor is shut down or stopped, it is depressurized inside. However, the pressure that is caught between the two seals remains and provides a constant prolonged pressure against the two seals creating undue wear and premature failure of the seals such as O-rings.
The present invention overcomes the disadvantages of the prior art by providing a system and method for automatically depressurizing the area between the two O-ring seals after the compressor unit has been stopped or shut down. In particular, a passageway connects the space between the two seals and formed by the adjoining surfaces to the interior of the unit such as a compressor. A one-way check valve is located in the passageway so as to allow pressure to enter the interior of the unit such as the compressor from the space between the seals but not to allow pressure to leave the compressor into the passageway during operation of the compressor. When the compressor is in operation, the passageway is held closed by a spring loaded sealing head in the check valve. Pressure in the compressor assists in holding the check valve in the closed position. Internal pressure in the unit seeps through the inner O-ring seal, through permeation, to a cavity between the inner and outer O-ring seals formed by the two surfaces joined together to form the chamber.
When the compressor is stopped or shut down and the inside of the casing is depressurized, the high pressure gas or fluid is trapped between the inner and outer O-ring seals. The trapped pressure follows the passageway connecting the space between the inner and outer O-ring seals toward the interior of the compressor. A check valve is placed in the passageway which will open to the internal side of the compressor allowing the high pressure trapped between the O-rings to automatically vent down when the compressor is depressurized internally, thus protecting and prolonging the use of the O-ring seals.
Thus, it is an object of the present invention to provide a device and method for depressurizing the area between two spaced high pressure seals such that any high pressure that seeps into the cavity between the seals during operation of the compressor or other device will not be maintained in the space to cause deterioration of the seals when the device is shut down.
It is another object of the present invention to couple a one-way check valve from the space between the seals to the interior of the compressor such that when the compressor is depressurized any high pressure remaining between the seals is automatically vented back into the interior of the compressor unit.